Setting Up a Twilio Messaging Service
A Messaging Service is a container that groups a phone number together with your A2P Campaign and shared webhook configuration. It's the thing your Campaign actually attaches to — not the phone number directly.
Why it's needed
A2P Campaigns don't attach to a phone number directly — they attach to a Messaging Service, and the Messaging Service is what the number is added to as a "sender." This layer of indirection is also what lets Twilio load-balance across multiple numbers behind one service if you ever need that, and it's where the shared inbound/status webhook URLs live.
Where to find it
In the console's left sidebar: Products and services → Communications → Messaging → Services.
Create a new service
Give it a descriptive friendly name — something like "Northside Medical Messaging" rather than a generic default. If you ever run more than one campaign on the same account, a clear name makes it obvious which service is which later.
Add your phone number as a sender
Inside the new service, add the number you purchased earlier as a Phone Number sender. A number can only belong to one Messaging Service at a time — if it's already assigned elsewhere, remove it there first.
Configure webhooks
Under the service's Integration/Webhooks settings, set:
Both as HTTP POST. See Webhook Configuration for the full walkthrough.
Find your Messaging Service SID and paste it into Linxi
The service's SID starts with MG. Copy it and paste it into the Messaging Service SID field in Linxi Settings → Number → Linxi Number.